The Greek historian Herodotus told the story of three hundred men from Sparta who bravely defended their country against the invasion of the Persian army. When the Persians launched an attack against Greece with a force of more than two million fighting men led by Xerxes, they had to pass through a little area known as the pass of Thermopylae, which was a small opening through some jagged cliffs.
The armies of Greece, obviously wanting to turn back their attackers, called for troops, but all they were able to rally were three hundred soldiers from Sparta, led by their king, Leonidas. He thought that if he could just hold the area for a while, reinforcements would come. So he led his three hundred men against the two million Persians at Thermopylae. Much to the surprise of everyone, the Spartans fought bravely and valiantly, and they were winning. Persian soldiers dropped one after the other. So Xerxes sent in his elite troops called the Immortals. These were the best men in his army, but the Spartans slaughtered the Immortals like everyone else. Eventually the Persians prevailed when a Greek traitor showed them the way to attack the Spartans from behind. All three hundred men were killed. And though they lost the battle, they didn't lose the war because the reinforcements finally came. The Spartans had bought much-needed time, and the armies of Greece ultimately prevailed against the Persians.
The same is true in the spiritual world as we fight a spiritual war. God can do a lot with a little. Our numbers may not be large, but our God is all-powerful. And as we go forward in His strength, we can make a difference.